Don't think you looked everywhere, the release notes state "1.13: Block connections are now serverside, you can enable serverside support by turning serverside-blockconnections: true in the config (It will use extra CPU and RAM, be warned)"

I will say this though, this man knows what he's doing, he's known how to do stuff for a good 5+ years.

He's the reason I enjoyed Towny so much and enjoyed mcmmo so much, he made custom achievements that gave points that were then used to buy mcmmo levels or VIP on the server I played on way back.

He made my first towny experience one of the best and it's because of that server I have made my own Towny server with some crazy stuff on it, this man here is one hell of a coder and glad he's still around.

Thanks for the memories Myles and keep it up mate. Also would be nice to know that old shop plugin you used back in 1.7.10 where items were limited in the shop and prices changed based off how much was in the shop.

Simply put one of the best resources out there, which makes it possible for your playerbase to connect to your older servers from every version that may be higher than the version that is currently on the server.
Also, even if you wanted for people on lower versions to connect, Myles here got you covered with ViaBackwards. The Via series is really greatly made, and even works on Bungee Networks with a single drag and drop, and you're good to go!

Have been using ViaVersion for a good while now, and I am definitely not gonna stop. Also kudos on the very frequent updates, really appreciate it.